Microbiological energy source for driving a consumer

ABSTRACT

A microbiological energy source for driving an electrical or mechanical consumer is disclosed, wherein at least one filling body having a piezoelectric or similar effect is received in a bioreactor. This bioreactor encloses waste water flowing through it, and contains a mixture of micro-organisms that form a positive pole and a negative pole of the energy source as a result of the microbiological decomposition of organic matter contained in the waste water.

The invention concerns a microbiological energy source for driving aconsumer, for example an electric motor.

In the field of waste water purification, efforts have been under way toconvert the biological processes of self-purification in bodies of waterunder natural conditions in temporally and spatially limited reactionsin waste water processing plants, so that the purification process mayunfold substantially more rapidly than in a natural way, and with areactor volume as small as possible. One essential aspect is the use andconcentration of the micro-organisms that are used for decomposition anddigestion of the undesirable constituents of the waste water.

In patent application DE 100 62 812 to the present applicant, amicrobiotic mixed culture for the treatment of polluted waste water isproposed, wherein a proportion of photosynthetically activemicro-organisms and a proportion of luminous bacteria are contained.Although this mixed culture has already been put to use successfully, itis a problem that a certain minimum proportion of luminous bacteria hasto be present in order to initiate the interaction betweenphotosynthetically active micro-organisms and the luminous bacteriadescribed in this application.

In order to improve growth of the micro-organisms, it is proposed in thefurther post-published patent application DE 101 18 839, to applyhigh-frequency oscillations to the micro-organisms intended for thepurification of charged waste water in a bioreactor. These oscillationsare in the ultrasonic range, and it could be noted that even atfrequencies in a range of 40 kHz a stimulation of growth of themicro-organisms flowing through the bioreactor can be noted. In theknown solution, the bioreactor used is a bulk filling material, with thebulk material consisting of permanent-magnetic and piezoelectric fillingbodies preferably prepared from ceramic materials.

Particularly in waste water processing technology, efforts are made toenergetically convert the products occurring in the waste waterpurification, in order to keep the energy requirement of the overallplant at a minimum. Thus, e.g., the biogas produced in microbiologicalconversion of the solids occurring in the waste water purification isutilized for energetically supporting energy-intense processes, such asa combustion, so that as little external energy as possible has to besupplied.

In contrast, the invention is based on the objective of exploitinginteractions between the product to be decomposed or converted, and themicro-organisms in the biological waste water or waste processing, interms of energy.

This objective is attained through a microbiological energy sourcehaving a bioreactor including at least one filling body having apiezoelectric or similar effect. The said bioreactor containsmicro-organisms which create a potential difference at the filling bodyowing to the microbiological decomposition of organic matter containedin waste water when waste water flows through said bioreactor so that avoltage may be drawn for operation of a working tool.

In accordance with the invention, the energy source has a bioreactorthat is provided with at least one filling body having a piezoelectricor similar effect and contains a mixture of anionic andcationic-micro-organisms forming, upon flowing through the bioreactorand the resulting microbiological decomposition at the filling body,positive and negative electrical poles where current for operation ofthe electrical consumer may be drawn. This electrical consumer may, forexample, be a drive mechanism for a work tool required in the wastewater processing.

Anionic and cationic micro-organisms are presently understood to bemicro-organisms that are present in preferred ranges of potential owingto physico-chemical reactions during metabolism, and thus gather in theranges of negative and positive poles. The voltage generated above thefilling body may then be utilized for driving an electrical consumer.

In accordance with the invention it is preferred if a filling body bulkmaterial is received in the bioreactor, with a respective positive andnegative pole then forming at the filling bodies owing to acorresponding orientation of the micro-organisms, and these single“dipoles” then aligning in such a manner that a directional magneticfield is generated above the bioreactor.

In a particularly advantageous variant, each of the filling bodiesforming a “dipole” is given a spherical shape and provided with aceramic coating that is interrupted at two poles in opposite locations.In this variant it is preferred if the coating consists of titaniumoxide. In addition to the bulk material forming “dipoles”, a bulkmaterial of permanent magnets may furthermore be provided in thebioreactor. These permanent magnets generate a magnetic field thatstimulates growth of particular micro-organisms such as, e.g., singlecell organisms, flagellates etc., to thus improve biological conversion.

In a preferred embodiment, these permanent magnets are given acylindrical shape, so that the turbulence of the medium flowing into thebioreactor, such as the waste water charged with organic matter, isimproved.

The filling bodies forming a “dipole” and the permanent-magnetic fillingbodies are preferably not received in the bioreactor as a solid bulkmaterial, but packing is performed such that the individual fillingbodies are movable relative to each other. It is being assumed that thisrelative mobility of the filling bodies allows for alignment of the“dipoles.”

The efficiency of the microbiological energy source may be enhancedfurther if hydrogen-producing micro-organisms, for example bacteria, areadmixed to the microbiological mixture, so that in the process ofbiological decomposition or conversion of the organic matter, hydrogenis generated which may be withdrawn from the reactor and exploitedenergetically. Here it is preferred if the hydrogen may be conductedacross a membrane forming a wall section of the bioreactor.

Further advantageous developments include:

1. a bulk material of filling bodies received in the bioreactor, whereeach of the filling bodies has a spherical shape and is provided with acoating that contains titanium oxide and is perforated in two oppositeregions. The filling bodies are arranged such as to be movable relativeto each other;

2. a bulk material of permanent magnets is provided in the bioreactor.The permanent magnets have a cylindrical shape;

3. a structure for withdrawing hydrogen formed during biologicalconversion. The hydrogen may be withdrawn across a membrane forming awall section of the bioreactor. Micro-organisms are present that formthe hydrogen as an intermediate or final product in the biologicalconversion of the organic matter of the waste water.

A preferred embodiment of the invention shall hereinbelow be explainedin more detail by referring to schematic drawings, wherein;

FIG. 1 in a schematic view of a bioreactor in accordance with theinvention for the formation of a microbiological energy source;

FIG. 2 shows a filling body of the bioreactor of FIG. 1, and

FIG. 3 is a sectional view of a head portion of the bioreactor of FIG.1.

FIG. 1 shows a bioreactor 1 holding waste water charged with organicmatter that flows through it. This waste water enters via an inlet 2into the bioreactor 1 having for instance the shape of a cylindricalcolumn, and exits from it via a central outlet 4. The bioreactor 1moreover includes a head portion 6 and a bottom part 8, whereby acylinder 12 of the bioreactor 1 accommodating a bulk material 10 isclosed on the end side, and having inlet 2 and outlet 4 formed therein.In the bioreactor 1 certain micro-organisms are moreover present whichshall be discussed in the following.

In the embodiment represented in FIG. 1, the bulk material 12 consistsof an upper bulk material portion with piezoelectric filling bodies 14and another portion located upstream and formed of permanent magnets 16having, for instance, a cylindrical shape. The two bulk materials offilling bodies 14 and permanent magnets 16 do, however, not have theform of a packed bed, but are arranged such that a certain relativemobility of the filling bodies 14 and permanent magnets 16 within therespective portion is possible. In other words, the bulk material ispacked very loosely.

FIG. 2 shows an enlarged representation of a piezoelectric filling body14 received in the region X.

Accordingly, the filling body 14 is about spherical in shape and has acore 1I of a ceramic material having piezoelectric properties. In theevent of a deformation of the core matrix under the influence ofmechanical force (pressure, pull, torsion), electrical charges arecreated at the surface of this material, or vice versa upon applicationof an electrical voltage, mechanical deformations of the ceramicmaterial can be noted which may be utilized, e.g., in microtechnologyfor controlling components, or in printer technology for the ejection ofink.

This core 18 of piezo ceramic has a coating 20 of titanium oxide (TiO₂)applied on it. The layer thickness preferably is in the range between200 to 1000 nm—different layer thicknesses are, of course, alsoconceivable. This coating 20 acts as a protective jacket, so that toxicconstituents of the piezo ceramic, such as lead, for instance, will notinteract with the waste water.

As is moreover indicated in FIG. 2, following application of the coating20, the filling body 14 is dotted in two diametrically locatedregions—in other words, dot-shaped perforations of the coating arecreated in these regions 22, 24, so that the core 8 contacts the wastewater in these dot-shaped portions. These contact regions are, however,made to be very small to preclude the occurrence of interactions withthe piezo ceramic likely to contaminate the waste water.

FIG. 3 shows a detail Y of the head portion 6 represented in FIG. 1.Accordingly, this head portion includes an outer jacket 26 encompassinga membrane 28. The latter may be manufactured, e.g., of ceramic materialand has an active pore width permitting withdrawal of hydrogen (H₂) fromthe bioreactor 1 through the membrane 28 via outlet openings 30. Thepore width of the membrane 28 is, on the other hand, too small to allowwaste water or other constituents of the waste water or micro-organismsto leave through the outlet openings 30.

Thanks to this design of the bioreactor 1 it is made possible that thewaste water is extracted via outlet 4, while hydrogen generated duringthe biological conversion—to be described in more detail hereinbelow—maybe supplied to another use via the membrane 28.

As was already mentioned at the outset, the bioreactor 1 or the enteringwaste water contains a biological mixed culture having a predeterminedcomposition. Details of this biological mixed culture are described inthe application DE 100 62 812, which is hereby included by reference.For better comprehension, only the essential components of the mixedculture shall be explained. It contains a proportion ofphotosynthetically active micro-organisms and a proportion of luminousbacteria or light-emitting micro-organisms having a similar activity,that are dispersed in a broad-band biological solution and are added tothe waste water. The interaction between the photosynthetically activemicro-organisms and the luminous bacteria as described in the aboveidentified patent application has the result that the photosyntheticallyactive bacteria are stimulated to photosynthesis by the luminousbacteria. The micro-organisms bring about photosynthesis with hydrogensulphide and water as an educt and liberate sulphur or oxygen. Moreoverthey may fix nitrogen and phosphate, and decompose organic and inorganicmatter. The mixture moreover contains additional micro-organismsgenerating hydrogen during the microbiological conversion.

Photosynthetically active micro-organisms that are facultativelyphototropic are preferred in the supplied microbiological composition.Phototropic facultatively means that the micro-organisms can grow bothunder anaerobic conditions in light and under aerobic conditions in thedark.

Among the photosynthesis bacteria there are gram-negative aerobicrod-shaped and circular bacteria and gram-positive circular bacteria.These may include endospores or be present without spores. Among themthere are for instance also gram-positive actinomycetes and relatedbacteria.

In this context it is also possible to name nitrogen-fixing organisms.Among these there are, e.g., algae, such as Anabena Nostoc in symbiosiswith Azola. Moreover it is possible to name actinomycetes, e.g. Frankiain symbiosis with alder and bacteria, such as Rhizobium in symbiosiswith laguminosae.

Moreover it is also possible to use aerobic algae, azotobacter,methane-oxidizing bacteria and sulphur bacteria. Among these there arealso green sulphur bacteria and brown-green photosynthesis bacteria.Here one may also name non-purple sulphur bacteria and purple sulphurbacteria.

It is preferred if, in the microbiological composition in accordancewith the invention, prochlorophytes, cyanobacteria, green sulphurbacteria, purple bacteria, chloroflexus-type forms and heliobacteriumand heliobacillus-type forms are contained as facultatively phototropicmicro-organisms. The above named facultatively phototropicmicro-organisms may also be present as mixtures of two or more of them.In a quite particular embodiment, all six of the above namedmicro-organisms are present as a mixture.

The light which powers photosynthesis originates from the luminousbacteria contained in the microbiological composition of the presentinvention as the second essential component. These luminous bacteriapossess luminosity, i.e., they are capable of emitting photons. This isa System that operates enzymatically. As an example, one may here namethe luciferin/luciferase system.

In one preferred embodiment, Photobacterium phosphoreum, Vibriofischeri, Vibrio harveyi, Pseudomonas lucifera or Beneckea are containedin the mixture as luminous bacteria. It is also possible to select amixture of at least two of these.

In order to optimize the microbiological composition of the invention,additional constituents may be contained in it. Preferably suchsecondary constituents are plant extracts, enzymes, trace elements,polysaccharides, alginic derivatives, other micro-organisms as above.The secondary constituents may be present in the microbiologicalcomposition of the invention either singly or in combination. The plantextracts may contain, e.g., ribwort, hops, etc.

Optionally added lactic acid bacteria serve to suppress pathogenic germsand lower the pH value.

As a nutrient solution for the microbiological composition of theinvention, a solution is generally used which contributes to making lifereadily possible for the constituents contained therein, in particularfor the micro-organisms. Here it is particularly crucial to allow fullinteraction of the photosynthesis bacteria and of the luminous bacteriato unfold. It was found that a biological nutrient solution includingmolasses, in particular raw sugar molasses or sugar beet molasses, issuited as a main ingredient.

The photosynthetically active micro-organisms and the luminous bacterianormally are present in the microbiological composition of the inventionin a ratio of 1:10 to 1:500. A preferred ratio is 1:100.

In the course of flowing through the bioreactor 1 together with thewaste water containing organic matter, the micro-organisms deposit in apreferred manner on the surface of the piezoelectric filling bodies 14.It was found that—presumably owing to the radiation emitted by theluminous bacteria—the titanium oxide coating is activated such that thesurface tension of the substance surrounding the piezoelectric fillingbody 6 is reduced, and these distribute homogeneously over the surfaceof the filling bodies.

There forms a kind of biofilm surrounding the filling bodies 6 andsubstantially made up of a mucus-type, extracellular polymer substance(EPS), in which the micro-organisms are embedded. This EPS preventstoxic substances in the waste water (such as heavy metals) frompenetrating inside the cells of the micro-organisms. The EPS moreoveracts as a diffusion barrier preventing substances required for thebiological conversion such as exoenzymes, for example, from beingdiffused to the outside. The EPS acts like a semi-permeable membranethat supports decomposition of the organic matter dissolved in the wastewater. Depending on the kind of micro-organisms, they deposit in apreferred manner in the range of regions 22 or 24. Moreover bacterialiving in symbiosis with other used bacteria use the EPS as a means tobe able to remain physically close to these bacteria.

Owing to the reduced surface tension of this biofilm, it is practicallynot possible for contaminants contained in the waste water to settle onthe surface of the filling bodies, for they are eroded by the biofilm,and the latter is deposited on the titanium oxide layer with a highstrength of adhesion.

With use of the mixed culture developed by the applicant, luminousbacteria and photosynthetically active bacteria accumulate in thebiofilm, resulting in a kind of “luminous film” that surrounds the piezoceramic filling bodies 6.

It was found that in a region 22, preferably micro-organisms accumulatewhich obtain electrons from the reduction equivalents of theirsubstrates to transfer them to other recipients, whereas in the otherregion 24, preferably micro-organisms accumulate which reduceconstituents of the waste water, for example molecular hydrogen, as anelectron source for the metabolism. In other words, a negative and apositive pole form in the regions 22 and 24 depending on the kind of theaccumulated micro-organisms, so that practically each piezoelectricfilling body 14 by itself represents a kind of “dipole.” The lines ofmagnetic flux 32 of this microsystems are drawn in FIG. 2, with thecloud above the regions 22, 24 representing the micro-organisms.

It was surprisingly found that when the bulk material 10 is packed in asuitable manner, the single piezoelectric filling bodies 14 will align,when waste water flows about them, such that the lines of electric fluxextend substantially in parallel. An electric field in accordance withFIG. 1 forms the lines of electric flux 34 having approximately theshape represented in FIG. 1. Accordingly a positive pole (V+) and anegative pole (V−) form along the bioreactor 1 owing to the orientationof the filling bodies 14, so that a voltage may be drawn. According tomeasurements performed by the applicant, the formed electric field hassufficient strength to provide enough power for driving an electricmotor. This means that the electric field formed during the biologicalconversion of the organic matter of the waste water above the bioreactor1 may be utilized for driving an electrical consumer, for instance anelectric motor. In waste water purification plants it is particularlyadvantageous if this energy is employed for driving stirring means,screens, conveyors, or other apparatus of the waste water purificationplant.

The permanent magnets 16 arranged in the lower or upper part of the bulkmaterial on the one hand ensure the presence of a turbulent flow withinthe bioreactor 1 due to their sharp-edged configuration, and moreoverthe growth of certain micro-organisms is additionally stimulated by thispermanent-magnetic field.

As was already mentioned above, some micro-organisms are utilized whichform gaseous hydrogen as an intermediate or final product. Such hydrogenforms, e.g., during photocatalysis, with sulphate (SO₄ ²⁻) beingreduced, and hydrogen and sulphur being released. This gaseous hydrogenmay exit through the membrane 28 and the outlet openings 30 from thebioreactor 1 and is discharged through suitable discharge means, to beutilized in terms of energy. Thus it is possible, e.g., to energeticallyexploit this hydrogen obtained in bioreactor 1 in a fuel cell.

The above described bioreactor may thus have a twofold use, with formedgases and also formed force field being utilized for generatingelectrical or mechanical energy.

What is disclosed is a microbiological energy source for driving anelectrical or mechanical consumer, wherein at least one filling bodyhaving a piezoelectric or similar effect is received in a bioreactor.This bioreactor encloses waste water flowing through it, and contains amixture of micro-organisms that form a positive pole and a negative poleof the energy source as a result of the microbiological decomposition oforganic matter contained in the waste water.

-   1. bioreactor-   2. inlet-   4. outlet-   6. head portion-   8. bottom part-   10. bulk material-   12. cylinder-   14. piezoelectric filling body-   16. permanent magnet-   18. core-   20. coating-   22. dotted region-   24. dotted region-   26. outer jacket-   28. membrane-   30. outlet opening-   32. lines of magnetic flux

1. A microbiological energy source for driving an energy consumer,comprising: a bioreactor including one or more filling bodies having apiezoelectric effect; and a permanent magnetic field in the bioreactor,wherein: the filling bodies form electric dipoles due to deformationcaused by streaming pressure of waste water streaming through thebioreactor, and the bioreactor contains a mixture of anionic andcationic micro-organisms which, because of the microbiologicaldecomposition of organic matter contained in the waste water, accumulateat poles of the electric dipole and create a voltage difference, and thevoltage difference is capable of being supplied to a working tool. 2.The energy source in accordance with claim 1, further comprising a bulkmaterial of filling bodies that is disposed in the bioreactor.
 3. Theenergy source in accordance with claim 2, wherein each of the fillingbodies has a spherical shape and is provided with a coating that isperforated in two opposite regions.
 4. The energy source in accordancewith claim 3, wherein said coating contains titanium oxide.
 5. Theenergy source in accordance with claim 1, wherein a bulk material ofpermanent magnets is provided in said bioreactor.
 6. The energy sourcein accordance with claim 5, wherein said permanent magnets have acylindrical shape.
 7. The energy source in accordance with claim 1,wherein said filling bodies are arranged such as to be movable relativeto each other.
 8. The energy source in accordance with claim 1,including means for withdrawing hydrogen formed during biologicalconversion.
 9. The energy source in accordance with claim 8, wherein thehydrogen may be withdrawn across a membrane forming a wall section ofsaid bioreactor.
 10. The energy source in accordance with claim 8,wherein micro-organisms are present that form hydrogen as anintermediate or final product in the biological conversion of theorganic matter of the waste water.